This invention relates to a liquid crystal display device. More particularly, this invention relates to a driving circuit that improves response as a luminance change time of a liquid crystal.
Response of liquid crystals represents generally the time from the application of a voltage to a liquid crystal to the acquisition of desired luminance. This response includes a rise response τr when the state changes from a voltage non-applied state to a voltage applied state and a fall response τd when the state changes from the voltage applied state to the voltage non-applied state. According to Japanese literature, “The Latest Technologies of Liquid Crystals”, p48, published by Industrial Research Association, each response can be determined from the following formula:rise response τr=(ηi·d2)/(ε0·Δε·V2−Kii·π2)fall response τd=(ηi·d2)/(kii·π2)where:                ηi: viscosity parameter (coefficient of viscosity)        d: liquid crystal cell gap        Δε: dielectric anisotropy        V: applied voltage        Kii: elasticity parameter (elastic modulus)        
This response formula of the liquid crystal suggests that in order to improve the response by contriving the liquid crystal material, the viscosity parameter ηi of the liquid crystal material needs to be made small. To improve the response from the aspect of the production process of a liquid crystal panel, the liquid crystal cell gap d needs to be reduced. To improve the response by a driving circuit, a driving voltage (a liquid crystal applied voltage) needs to be increased.